I agree with this. I wonder if they would have gone in that direction with SM4 (since Peter kinda proposed in SM3). Can't know that now.

The problem is getting those younger actors to be willing to sign long deals for all of the films. If the SM films are successful enough for 4-6 films, the demand for those young actors (Garfield, Woodley, DeHaan, Stone, etc.) would skyrocket. Would you want to be tied down, playing the same character for 9-12 years while other studios are throwing big money your way with opportunities to branch out?

That being said, if it would work, I'd like that story concept you mention. Could get very deep.